This volume presents new texts of Cicero's dialogues on political philosophy, De Re Publica and De Legibus, together with corrected versions of the editor's previously published editions of Cato Maior de Senectute and Laelius de Amicitia. The texts are based on a full reconsideration of the manuscript evidence and are presented in a clear and readable form.

Does action always arise out of desire? G. F. Schueler examines this hotly debated topic in philosophy of action and moral philosophy, arguing that once two senses of "desire" are distinguished - roughly, genuine desires and pro attitudes - apparently plausible explanations of action in terms of the agent's desires can be seen to be mistaken. Desire probes a fundamental issue in philosophy of mind, the nature of desires and how, if at all, they motivate and justify our actions. At (...) least since Hume argued that reason "is and of right ought to be the slave of the passions," many philosophers have held that desires play an essential role both in practical reason and in the explanation of intentional action. G. F. Schueler looks at contemporary accounts of both roles in various belief-desire models of reasons and explanation and argues that the usual belief-desire accounts need to be replaced. Schueler contends that the plausibility of the standard belief-desire accounts rests largely on a failure to distinguish "desires proper," like a craving for sushi, from so-called "pro attitudes," which may take the form of beliefs and other cognitive states as well as desires proper. Schueler's "deliberative model" of practical reasoning suggests a different view of the place of desire in practical reason and the explanation of action. He holds that we can arrive at an intention to act by weighing the relevant considerations and that these may not include desires proper at all. (shrink)

The Irish poet W. B. Yeats once wrote, with great sapience and perception: Nor dread, nor hope attend A dying animal; A man awaits his end Dreading and hoping all. That death has ever been a problem to man is attested as far back as we can trace our species in the archaeological record—indeed, it seems to have been a problem even for that immediate precursor of homo sapiens, the so-called Neanderthal Man; for he buried his dead.

The phenomenon of probability backflow, previously quantified for a free nonrelativistic particle, is considered for a free particle obeying Dirac's equation. It is shown that probability backflow can occur in the opposite direction to the momentum; that is to say, there exist positive-energy states in which the particle certainly has a positive momentum in a given direction, but for which the component of the probability flux vector in that direction is negative. It is shown that the maximum possible amount of (...) probability that can flow “backwards,” over a given time interval of duration T, depends on the dimensionless parameter ε = (4ℏ/mc2T)1/2, where m is the mass of the particle and c is the speed of light. At ε = 0, the nonrelativistic value of approximately 0.039 for this maximum is recovered. Numerical studies suggest that the maximum decreases monotonically as ε increases from 0, and show that it depends on the size of m, ℏ, and T, unlike the nonrelativistic case. (shrink)

It has been shown earlier that while strict localization of the free Dirac particle is not describable within the usual mathematical formalism, it is possible to describe sequences of positive-energy states whose spread Δ x =〈(x−x 0)2〉 about any given point x 0 approaches zero, where x is Dirac's position operator. The concept of a generalized function is extended here to allow for the succinct description of localized states in terms of “Asymptotic Localizing Functions.” Localization of both the nonrelativistic particle (...) and the Dirac particle can be adequately represented in this new formalism. (shrink)

First published in 2002. Routledge is an imprint of Taylor & Francis, an informa company.